Apparatus for regulating the consistency of pulp or stock



H. G. CRAM APPARATUS FOR REGULATING THE CONSISTENCY 0F PULP OR STOCK 3Sheets-Sheet 1 Filed Sept. 28, 1936 INVENTOR. J M

ATTORNEY.

HAwR 8- 1940. H/G. CRAM 2.210.027

APPARATUS FOR aseum'rzm n na cousrs'wncx 0F PUL? on s'rocx Filed se t.2a, 1936 s Sheets-Shoot 2 x-f6, 1940. H. G. cam 2.210.027

APPARATUS FOR REGULA'I'IRG THE CONSISTENCY 0F PULP 0R STOCK Filed Sept.28 1936 3 Sheets-Sheet 3 INVENTQR.

ATTORNEY Patented Aug. 6, 1940 UNITED STATES PATENT OFFICE APPARATUSFORK REGULATING THE CON- SISTENCY OF PULP OR STOCK 3 Claims.

This invention relates to an apparatus for regulating the consistency ofpulp or stock for use in the making of paper or similar fibrousproducts.

The present application is a continuation in part of my application forApparatus for and method of regulating the consistency of pulp or stock,filed November 18, 1935, Serial No. 50,397.

One of the objects of the invention is to obtain close regulation of theconsistency of the pulp or stock and thereby increase the uniformity ofthe finished product.

Another object of the invention is to provide an apparatus which iscapable of automatically maintaining a substantially uniform consistencyand of maintaining any selected consistency over a rather wide range ofavailable consistency.

Another object of the invention is to provide an apparatus of thecharacter mentioned andhaving the advantages referred to and which issimple and durable in its construction; reliable andsensitive inoperation and easy and comparatively inexpensive to manufacture, installand maintain.

Other objects and advantages reside in certain novel features of theconstruction, arrangement and combination of parts which will behereinafter more fully described and particularly pointed out in theappended claims, reference being had to the accompanying drawings,forming a part of this specification, and in which:

Figure 1 is a diagrammatic view partly in elevation and partly invertical section showing one type of apparatus embodying the presentinven- 1 tion;

Figure 2 is a fragmentary view similar to Figure 1 but illustratinganother embodiment of the invention;

Figure 3 is a view partly in side elevation and I partly in longitudinalvertical section and on an enlarged scale and illustrating oneconstruction of the regulator box;

Figure 4 is a fragmentary view in front elevation illustrating the drivefor the dispersing drum of the regulator box;

Figure 5 is a view in horizontal cross section taken on line 5-5 ofFigure 3;

Figure 6 is a fragmentary diagrammatic view 59 illustrating the generalcharacter of the compensating pneumatic actuator interposed between thefloat of the regulator and the valve which controls the supply ofdiluting water to the stock: Figure 7 is a view in transverse verticalsection taken on line of Figure 9, parts being shown in section for thesake of illustration;

Figure 8 is a view in longitudinal "vertical cross v section taken online 8-8 of Figure 9, parts being shown in elevation for the sake ofillustration;

and

Figure!) is a view in horizontal cross section taken on line 9-9 ofFigure 8, parts being shown in top plan for the sake of illustration.

The general construction of the apparatus is the same in all embodimentsof the invention and is illustrated in Figure 1. As there shown, thestock is supplied by a pipe l! to a stock tank ll equipped with asuitable motor driven agitator diagrammatically illustrated at H.Usually the stock is fed through the pipe ID from a heater (not shown)or other suitable source of supply. From the outlet of the stock tank IIa pipe l3 leads to a stock pump M which may be driven by an electricmotor IS. The stock pump ll discharges into the lower end of a verticalpipe is which communicates at its upper end with the lower end of acompartment I! of a regulator box designated generally at N. Theregulator box I! is fabricated of sheet metal as illustrated in thedrawings and is provided with internal partitions I'l'and 22' todeflne'the compartments or chambers referred to. An overflow pipe 20 leads backfrom another compartment 2| of the regulator box to the stock tank ll.Still another compartment 22 of the regulator box has a pipe 22 leadingtherefrom and discharging into a whitewater and mixing box indicateddiagrammatically at 24. A valve 25 provided. with a hand wheeladjustment 26 may be employed to regulate theflow through the pipe 23. Apipe 21 leads from the box 24 to the suction side of a pump "driven byan electric motor 29 and having its'outlet connected to a pipe 30 whichleads pulp is delivered by a conduit 32 to a head box 33 of the papermakingmachine and in accordance with the usual practice flows from thehead box onto the Fourdrinier wire 35of the paper making machine.

The description thus far applies to all forms of the invention. In fact,the several forms diiler principally in the manner of supplying dilutingwater to the stock and in the particular character of the structure byvirtue of which the regulating action is had.

In the forms of the invention illustrated in Figures 1, 3 to 4,inclusive, andT'to 9, inclusive, the water or other liquid used fordiluting the to a screen 3!. From the screen 3| the stock or stock issupplied to the compartment I! of the regulator box. li'or this purposea water supply pipe 36 is provided and terminates in a. perforated inletpipe 31, the pipe 31 extending through a suitable packed bearing 38provided on the regulator box and projecting into and horizontallyacross the compartment ll near its upper end. A dispersing drum 39surrounds the portion of the perforated inlet pipe located within thec0mpartment l1. As illustrated in Figures 5 and 9, the body portion ofthis dispersing drum is cylindrical and is carried by circular andsuitably flanged end plates 40 and 4!. Between the hubs or innerportions of these end plates and smooth imperforate sections of theinlet pipe 3'! suitable bearings 42 may be provided. The. end plate 4|has a short shaft 43 integral therewith and rotatably fitted in a packedbearing 44 provided therefor on the front wall of the regulator box.Outwardlybeyond the bearing a beveled gear wheel 45 is pinned orotherwise fixed to the short shaft 43 and meshes with a beveled drivingpin 46 secured to the armature shaft of an electric motor 41 which. maybe supported on a bracket 48 carried by the regulator box,

In the operation of the machine the motor 41 rotates the dispersing drum39 and this, together with the perforated character of the drum and theinlet pipe, insures the uniform distribution of'the diluting liquid aswell as an agitation of the stock or pulp.

Flow of the diluting liquid through the pipe 35 and to the dispersingdrum is regulated by a valve designated generally at 50. As illustratedin Figure 6, the valve is biased to closed position by means of a spring5| which encircles its stem and bears at its lower end against ashoulder 52 and at its upper end against a diaphragm 53 which isconnected or suitably secured to the valve stem. A suitably shapedcasing section or cover plate 54 coacts with the diaphragm 53 to providea pressure chamber 54' thereabove.

Pressure issupplied to the chamber above the diaphragm by-means of 'apipe 55 which leads to the chamber from a suitable source of supply ofcompressed air. In this pipe 55 a reducing valve 55 and shut-off valve51 are incorporated. The pipe 55 has a branch 55 which communicates withthe atmosphere to vent the pipe 55.

The venting action of the branch 58 is regulated bya suitable valve 59which is controlled by an operating lever 60 suitably fulcrumed as at 5|and appropriately connected to the floats of the regulator as willhereinafter more fully appear. The illustration in Figure 6 is aschematic one to designate the fundamentals ofithe pneumatic control Pactually used. In actual practice this control may be obtained on theopen market. One suitable type is manufactured by the Mason- NeilanRegulator Company of Boston, Massain the structures shown in'Flgui-es 1and 2 and,

in fact, differs principally only in the provision made for supplyingthe stock from the system to the float controlled consistency responsivedevice.

Asbest illustrated in Figure 3, the consistency responsive devicecomprises an elongated tapered float 55 which'is submerged at all timesin a,

column Of the pulp or stock being handled, the

column being designated generally at C. The column in which the float 55is submerged is constituted by a lower pipe section 56 and anintermediate internally tapered ring 51 and an upper and larger pipesection 58, which are suitably fastened together and which may besuitably strengthened by connecting angles 59. The upper end of thiscolumn is open and the lower end freely communicates with one leg 10 ofa U-shaped conduit II, the other leg 12 of which communicates with thelower end of the compartment 22.

Secured to the float and extending axially therethrough is an elongatedstem or rod 13 which is of very small diameter. The lower end of thisstem or rod projects beyond the lower end of the float and carriesangularly spaced and transversely extending guide pins 14 which ooactwith the inner wall of the lower column section .55 to constrain thefloat to proper move- I1 and overflows over the upper ends of the par-.

titions I l' and-22' which define this compartment, the partition 22'being slightly lower most of the pulp flows into the compartment 22 andfrom this compartment flows through the pipe 23 to the machine and alsothrough the U-shaped conduit II to the column C. It the pulp is of theconsistency for which the machine is set this operation will go on inthe manner stated, the pulp which spills over the partition 11' and overthe upper end of the column C flowing back to the stock tank through theoverflow pipe 2|. If, for example, the consistency desired is 3% and thepulp supplied to the regulator box rises to 4% the increase in theconsistency of the pulp rising up through the column C will cause thefloat to be elevated a certain distance or increment, thereby swingingthe lever 50 in a counterclockwise direction as viewed in Figure 6, andclosing the vent 58. Pressure then builds up in the chamber 53' andopens the valve 55 against the action of the spring. This allowsdiluting water to flow through the pipe 35 I and the dispersing drum 3!into the pulp in the compartment I! to dilute it and bring it down tothe proper consistency. Thereupon the float resumes its former position"d the water supply valve 50 is closed. If pulp of higher consistency isagain supplied the action is repeated. Generally speaking, the operationmay be characterized as sample and check, sample and check.

In the type of structure shown in Figure 2 the pulp supplied to thecolumn 0 is taken from the pipe I 6 by means of a pipe 16 which leadsfrom the pipe Hi to the lower end of the column 0.

The diluting water may be supplied as before or it may be carried intothe pipe It at some point between the regulator box and the point atwhich the pipe 16 communicates with the pipe I5, as

22' may be omitted. With either arrangement the stock is always suppliedto the column 0 before it has. been diluted and correction forconsistency variations are made continuously.

. i shown in Figure 2. In the latter case partition The type ofapparatus shown in Figures 7 to 9, inclusive, is a combination of bothtypes hereinabove described. Generally speaking, a double floatarrangement is utilized, one float being responsive to pulp which hasbeen diluted and the other to the pulp of its original consistency, thatis, the consistency which it has when it is pumped from the stock tank.As shown in Figures 7 to 9, inclusive, the regulator box is internallypartitioned as before to provide the compartments I1, 2! and 22. Thediluting water is supplied to the compartment H through the perforatedinlet pipe 31 of the rotating dispersing drum 39. Pulp is supplied tothe compartment I! through the pipe [6 and is taken from the compartment22 by pipe 23. However, instead of having only one column C two suchcolumns designated at C and C are provided. They are of identicalconstruction and correspond exactly to the column C shown in Figure 3.However, the column C is supplied with pulp by a U-shaped conduit 80,one leg Bl communicating with the lower end of the column C while theother leg 82 communicates with the bottom' of the compartment l1.Inasmuch as the pulp being supplied to the compartment H from the stocktank is continuously rising upward in this compartment it is not di-'luted at the bottom so that the pulp taken to the column C is of thesame consistency as the pulp in the stock tank. The pulp supplied to thecolumn C is carried over from the compartment 22 by means of a U-shapedconduit 83 and, of course, this pulp has been diluted to the extent thatwater is supplied to the pulp by the perforated dispersing drum 31. y

The stems 13 of the floats of the columns C and C are suitably connectedto a cross bar or cross head 85. One type of connection contemv plates apivotal connection 86 to one of the stems and a pin and slot connection81 to the other. Through suitable motion transmission mechanism, such asindicated at 88, the cross head 85 is utilized to operate the ventcontrolling valve 56.

This type of structure gives much closer and more sensitive regulationthan the other two types disclosed although the other two find veryadvaning up through the column C will lower immediately to close thewater supply valve and allow the necessary correction to occur in theconsistency of the pulp. Of course, it is also true that if the float Cshould fail to open the valve enough or maintain it open long enough tobring about the desired dilution the pulp flowing through the column Cwould act on its float to supplement the action of the float in thecolumn'C' In all embodiments of the invention, the floats are entirelysubmerged. This is an important feature of the invention as it increasesthe accuracy and sensitivity of the regulator.

In this connection it shouldfibe observed that the floats in anyembodiment of the invention are entirely submerged in any of theirpositions and that there is a minimum and uniform transverse area,namely, the upper portion of the stem 13, projecting up through thesurface. of the stock at all times. This means there is a minimum andflxed uniform increment or change in weight of the regulator per unitrise for the reason that the decrease in displacement of liquid per unitrise of the regulator is uniform. The floats in all embodiments of theinvention are special in their nature in that they are entirelysubmerged in all positions and in that were it not for the velocity inthe upward flow of the pulp in the columns in which these floats arepositioned they would immediately sink.

The volume rate of flow between each float 65 and its cooperating ring61 is established by the constant differential in head between thecompartment 22 and the overflow of the column in which the float isoperating. The taper of each of the floats determines the area ofopening between it and its ring 61 in any particular vertical positionof the floats. And the mechanism which actuates the valve 50 is such toobtain a correspondence between the float positions and the valvepositions. For example, if the float is considered as having sevendifierent vertical positions and the valve is also considered as havingseven different positions between its fully open and its fully closedpositions then the valve positions will always correspond exactly withthe float positions.

An increase in the fiber solid content of the liquid passing through theopening between any ring 61 and its-float acts as a deterrent to theflow because of friction set up thereby between the float and its ring61 and this results in an increased upward pressure on the float. As aconsequence the float will rise vertically until the area of the openingbetween it and its ring Bl is sufficient to'compensate for the increasedconsistency. The rise vertically of the float as efiected by increase inconsistency is transmitted to the valve 50 in the water line to injectthe proper amount of water into the stock.

With the thinning water entering the stock ahead of the regulator orfloat 65 it is simply a matter of sample and adjust to the requiredconsistency with the thinning water. If the water is added after thestockis past the float the supply ency of the stock passing the float toreduce the stock to the required predetermined consistency.

' From the foregoing it is obvious that the compartment I'l serves as amain supply compartment, that the compartment 2| provides an overflowcompartment and that the compartment 22 functions as a discharge ordelivery compartment or chamber.

From the foregoing, it will be understood that the present inventioninvolves an apparatus for regulating the consistency of fibrous stock inliquid suspension and that the method consists basically in continuouslybypassing a sample of said stock through a vertical column submerging inthe column a float whose vertical position varies directly as changes inconsistency and utilizing the changes in the vertical position of thefloat to control the amount of diluting liquid supplied to the stock. Inits most advanced and refined form this apparatus is somewhat moreelaborate in that instead of by-passing a sample through a single columntwo separate samples are bypassed through separate columns, one samplebeing of the stock as it is taken from the source of supply and theother being the stock after the diluting liquid has been added thereto.As in the basic form of the apparatus a float is submerged in each ofthe two columns and the float is so constituted as. to vary in itsvertical position directly in accordance with variations in theconsistency of the stock. The resultant of the combined vertical ofdilutent water is co-ordinated to the consistmotion of the two floats isu tilized to exercise the control over the supply of the dilutingliquid.

While I have shown and described several types of apparatus it is to beunderstood that these have been selected for the sake of illustration or.7

example and are not intended as restrictive, various changes beingcontemplated within the spirit of the invention and the scope of thesubjoined claims.

The invention claimed is:

1. An apparatus for regulating the consistency of fibrous stock inliquid suspension comprising a regulator box having internal partitionsdefining a supply compartment, a delivery compartment and an overflowcompartment, a pipe line for supplying stock to the lower end of thesupply compartment, said stock flowing over one of said partitions intosaid delivery compartment, means for supplying diluting liquid to theupper portion of the supply compartment, means in the overflowcompartment defining two vertical columns, the upper ends of whichdischarge into said overflow compartment, a connection between one ofsaid columns and the lower end of the delivery compartment, a connectionbetween the other of said columns and the lower end of the supplycompartment, a float submerged in the stock in each-of said columns andadapted to individually change their vertical positions in accordancewith the changes in the consistency of the stock in their respectivecolumns, and means utilizing the resultant of the vertical movement ofthe two floats to regulate the action of p the liquid supply means tocause it to vary the amount of liquid dilutent supplied to the stock.

2. A device responsive to variations in pulp consistency comprising avertical conduit open at its upper end, a ring incorporated in theconduit below the top of the dischargeend thereof and having its innerwall upwardly and outwardly tapered, a substantial length ofsaid-conduit above said ring being of uniform cross sectional area, anda correspondingly tapered float cooperable with said ring, said floatrising and falling vertically in accordance with variations in theconsistency of the stock flowing past it and the ring, said ring andsaid float being so designed that as the float rises the area of thepassage between the float and the ring will be increased whereas whenthe float lowers the area of the passage between the float and the ringwill be decreased.

3. A pulp consistency regulator comprising means for supplying dilutingliquid to the pulp, operating mechanism for said means, and a controldevice responsive to variations in pulp consistency and governing theaction of said lastnamed mechanism and comprising a vertical conduitopen at its upper end and having a portion of its inner wall below'saidopen upper end upwardly and outwardly tapered, a substantial length ofsaid conduit above said tapered portion being of uniform cross sectionalarea, and a weighted float disposed in said conduit and having itsperiphery downwardly and inwardly inclined whereby upon variations inpulp consistency the float will be raised and lowered and the area ofthe passage between the float and the tapered portion of said wallvaries, said float being interrelated with said operating mechanism.

- v HERVEY G. CRAM.

